Tires are one of the most forgotten parts of our airplanes. After all, we spend a majority of our time flying through the air, our tires getting a “free ride,” as it were, not in contact with the ground. To the dismay of engineers and aircraft designers everywhere, most of the time an aircraft is in use, its tires are just sitting there being heavy. Unfortunately, because of their seemingly secondary role, pilots tend to neglect their tires to some extent, downplaying problems that could eventually come back to bite them in the tail – HARD!
LET’S START WITH THE NOTORIOUS SHORT FIELD LANDING and the flat spot on the tire that develops as a result of it. The pilot got a little too heavy with his foot while the aircraft was still a bit too light and the right main got to howl for a few seconds. While the time was short, it was long enough to burn the tread down to the core of the tire. Mind you, the pilot couldn’t see the cords showing through, so he thought he would be just fine to keep flying with the tire for a few more months, until his next annual was up.
AH, THE BEST LAID PLANS… Murphy is a full-time occupant of any airplane, whether it is on the ground, or flying through the air, and his law is always in effect. Our pilot did in fact fly another fifteen or twenty times on that tired, old tire, with no problems at all. The landings were all smooth, the runways sublime, and the rollouts came off without a hitch.
WAITING FOR THE OTHER SHOE TO DROP? The problem with a tire that is worn down to no tread is that there is a very narrow margin between rubber and tire failure. Tires that fail in landing can rate from a nuisance that need not even be thought about, to a dangerous ground loop-causing monster followed by a prop strike and wing damage.
WHICH ONE DO YOU THINK YOU’LL GET? Remember, Murphy is in play here. You will be in a high energy landing, with more speed than runway. You will have to make a choice between getting on the brakes hard, or taking it around for another pass. If you choose to get on the brakes — hey, you’re already on the ground and that is the final objective — Murphy’s Law states that the flat spot on your tire will end up matched to the pavement, and that tire baby, she’s a gonna BLOW!
KA-POW goes the tire, as the braking action quickly goes through the remaining rubber, through the casing, and into the tube.
SWERVE goes the airplane, as all the air goes out of one of the main landing gear tires, increasing the rolling drag on the side that just went flat, and causing the pilot to push hard on the opposite rudder pedal to keep the aircraft in control. If you have wheel-pants, things could be even more complicated…
MASH, CRASH, SMASH, SNAP goes the airframe, if the tire happens to fail at too high a speed to keep the plane under control, and the airplane swerves out of control off the runway…and that’s if the pilot gets lucky, and there isn’t another plane waiting at a taxiway as he lands and goes out of control…
NOBODY PLANS TO HAVE AN ACCIDENT. However, the decisions we make as pilots can set us up to have one. Take a look at your tires today. Do they have any flat spots? Is there enough tread left to allow them to continue to be used safely? Are the sidewalls weather checked and damaged? Are there any deep cuts in the treads? Can you see the cord showing anywhere? Look hard at your tires, and don’t forget to check them again as you pull the plane out and expose the spot the tire contacted the ground. If the aircraft rolls on nearly flat ground, it may stop there. Taking the RIGHT action and take one challenge out of your next landing.